Eeewww! I'd wipe down with a very diluted (ten to one) solution of bleach and water. That's what hospitals use on hard surfaces.

You should check with your local granite suppliers to be sure, but I think the problem with disinfectants on granite is that it could remove the sealer, which should be reapplied periodically anyway. Mine comes in a spray can and it just sprays on. So -- my point is you can disinfect, then reseal if necessary. But if you can't get rid of the nasty vermin, you'll have to keep doing it. Eucalyptus oil is a safe disinfectant, I think. You can mix it in a spray bottle with water. Whether it will be strong enough or if it will break down the granite sealer -- I'd check with the tile and stone experts on the kitchen forum. I use vinegar and water on my tile floors, but on sealed granite -- again, the kitchen people are a good source of information. You should get plenty of opinions anyway. Good luck